An electronic bulletin board (also referred to as a bulletin board simply), which is provided in a storage device of a server constituting a computer network, is widely used as a site where users of terminal devices (clients) can read and write information freely. Such electronic bulletin boards are on public view and are read or written by any unnamed person as a general rule, but it is also common to provide a forum or the like to which only registered members can get access by an authentication procedure such as log-in.
Such electronic bulletin boards are used for providing sites for communication and information sharing among members belonging to a specific group. Compared with mailing list or broadcasting transmission by using electronic mail only, the electronic bulletin board has a merit that information sharing among members can be achieved in real time.
In a conventional electronic bulletin board, a notice mail is sent to members who did not read specific information so as to encourage them to read the information and to prevent failure of information transmission. However, a sender of the information may be required to decide whether the bulletin information should be finished or not depending on level of importance of the information or others when an expiration date of the bulletin information has come and there is still a member who has not read the information yet. In some cases, the expiration date should be postponed so that the information can be shared by every member.
In addition, if a change is made in the bulletin information (text and related data), individual communication to each member by electronic mail or telephone may be necessary so that the information sender can check whether the change is transmitted to each member correctly. For this case, a method is proposed in which a notice of the change is automatically transmitted to designated addresses (see Japanese unexamined patent publication No. 6-14140). In this method, however, the notice of the change is sent to every member to be provided with the information without checking whether the member has read the information or not. In addition, an operation may be performed in which the revised bulletin information is put up as new bulletin information, or statuses of all members to be provided with the information including members who have already read the information are reset to “not read”.
Furthermore, a method is generally used in which the information is provided to not all members but members who satisfy a predetermined condition, so only the members designated by the information sender can read the information. In this case, the reader can know that the information is restricted to specific members but cannot know the specific range of members who can read the information.
It is very hard to manage manually the above-mentioned expiration date of bulletin information or read and unread statuses for every member to be provided with the information. If the management is not performed appropriately, a problem may happen such that the expiration date of important bulletin information is not postponed though there is a member who has not read it yet, resulting in that the important information is not shared by all the members.
In addition, many problems may happen when the bulletin information is revised. First, if the notice of the change is sent not only to members who have not read the information but also to members who have already read the information, it may permit waste in operations or inundation of unnecessary information, because the notice of the change is sent to members who have not read the information and do not need the information. Secondly, if only resetting the statuses of read or unread of every member to “unread” when the bulletin information is revised, there is a possibility of overlooking the bulletin information after the revision by a member who has read the information before the revision because he or she may misunderstand the bulletin information as already read when viewing it without any motivation to confirm contents of the revision. Thirdly, if the status is still “read” after the notice of the change is sent, there is no means for checking whether contents of the revision was confirmed or not, so that members may have different recognitions about the information.
Furthermore, if the range of the members who are provided with information is restricted, a reader can know that the information is restricted to specific members but cannot know the specific range of members who can read the information. In addition, the reader cannot know the situation about the members who have read or not read the information in real time. For this reason, prompt decision and action cannot be achieved by the communication in the information sharing range. There is a possibility of leaking information to a person who is not member to be provided with the information due to a delusion or a presumption of a reader of the information, for example. On the contrary, if such a leakage of information is cared too much, there is a possibility of insufficient communication and share of information among members in a working place or the like by utilizing a bulletin board management system.
The present invention is made to solve the above problem, and an object of the present invention is to provide a bulletin board management system and a computer program for realizing the system, in which failure of information transmission is prevented effectively, so that promotion of communication among members and prevention of information leakage can be achieved by small effort of management.